Lawrence (Tom Hanks), a partying, womanizing, college student with a gambling problem, runs up a large bill with a powerful gangster who has waited long enough for his money. The obnoxious, smart mouthed Lawrence was born into a lot of money, but his father refuses to bail him out of this one. When a thug comes to collect, Lawrence remembers that his friend Kent is flying to Bangkok to join the Peace Core.
Lawrence races there to trade places with Kent to avoid getting killed. Lawrence no more then gets on the plane and realizes that he is not fitting in. He is seated next to the overly talkative and annoying Tom Tuttle (John Candy) who is a die hard and can't wait to get started. Before the flight even lands, Larry wires his dad, to get out of going and then seats next to the beautiful Beth Wexler (Rita Wilson) and makes a move. Disgusted by his dishonest playboy maneuvers, she tries to avoid him. The problem is that Tom, Larry, and Beth are taken to a secluded village in a dangerous part of the jungle, to build a bridge. Soon after Larry starts teaching the locals how to play cards, he encounters the ruthless drug lord of the land. He gives Larry 6 weeks to finish the bridge so it can be used to traffic drugs faster. He has no choice but to agree to make it happen because his life depends on it.
Meanwhile, Tom has been kidnapped, and brainwashed into a communist army Hell bent on stopping the bridge from being built. Larry gets the locals and Beth to start working themselves sick.
As Tom returns he does not let on that he is there to stop the construction. Of course he is amazed that Larry, the self absorbed slacker has got a good start and is organizing the locals in an impressive way. Of course he gets his hands on some perks from home and wins favor with Beth again, after he opens his own bar. The bridge gets built and life is good, well, unit Beth gets kidnapped. An attempt on Larry's life fail and he and his local friend, At Toon set out on a zany adventure to rescue his new love, Beth. Escaping the drug lord's palace and henchmen is no easy task, but they get back to the village and they prepare for a counter attack.The plan is to blow up the bridge, but Tom has gone nuts and tries to blow them up. Then, all unholy Hell breaks loose and the village comes together. As the drug lord's regime come from one direction to cross the bridge, the commies come from another. The villagers'attempt to blow the bridge fails and Larry must play the hero and go out to the middle of it and fix the detonator. Of course he succeeds and he and Beth stay in the village to live happily ever after.